#include <stdio.h>
int main( )
 { 
    float x,y;
    printf("x=");scanf("%f",&x,&y);

    if (x<=2) y=x;
    else 
        if (x<=4) y=1+x/2;
        else y=2+x/4;
    
    printf("\ny=%6.2f",y);
    return 0;
 }

